What version of InDesign? What computer platform?
Are you using the Kindle plug-in for InDesign to produce output, or are you creating an EPUB and using Kindle Previewer to gene ate the .mobi file?
Version: InDesign CC
I'm not familiar with the Kindle plug-in, but it sounds like something worth looking into.
As I mentioned in the original post - I'm exporting from InDesign to an EPub (fixed).
Yes, I use the stand-alone Kindle Previewer to load the epub file and generate the mobi file.
I'm using a PC with Windows 7.
I missed the line about choosing export to Fixed Layout EPUB in InDesign CC, sorry.
I've moved your question to the InDesign EPUB forum which is being monitored by the engineers who are designing the feature.
I don't believe that they are yet supporting export to the Kindle at the point because of the differences between Kindle support for Fixed Layout and the EPUB 3 standard which they are aiming for, but we'll see what they say.
Welcome to the world of inconsistent EPUB readers.
Fixed Layout is relatively new and many of the readers have not caught up to this capability.
Likewise the handling of embedded fonts is also inconsistent - I've had poor luck in the past in regard to Kindle devices so perhaps some of them are better now.
Our export takes the metrics of the fonts as composed in InDesign and marks up every word in the exact places where it is supposed to go - but we have to let the reader/device compose the word itself and if the font selected or the composed width of the word is different than InDesign did then you get bad gaps or overlaps between words.
The Kindle plugin does not support CC and does not support Fixed Layout.
The Kindle folks have their own history and challenges and Fixed Layout from InDesign is relatively new (few weeks old) and so it is not something that has been immediately on their radar.
I encourage you to contact the Kindle team and let them know of your interest in Fixed Layout through InDesign - our goal is to export a very vanilla version of fixed layout and let the devices sort it out and right now that means EPUB 3 devices such as iBooks, Kobo and Readium.
Architect, InDesign Engineering
Thanks for the detailed reply. I did not realize I was that close to the leading edge by using the Fixed Layout ePub. But hopefully support for it will accelerate, as you've indicated. I've continued experimenting with my formatting and a simple font face change improved the appearance of my headings measurably. They are not what I would consider perfect, but it's a step forward. However, I applied the same font face to my body text, and it came out all bunched up on most pages. One step backward, now for another step forward.
If you'd ever like to have a guinea pig for any Fixed Layout testing, tag me and if schedule allows I'll help out.